Originally Posted by joejones

This is a good one too, and I like the parallel with "Foggy Bottom" in Washington DC.

"Roppongi" means "six trees" and I have heard two theories as to its origin -- one saying that there were actually six trees there that served as a landmark at some point, and another saying that it was named for six residents who had characters for trees in their family names.

"Ikebukuro" means "pond bag" and is supposedly named after... wait for it... a pond shaped like a bag.